Method of and apparatus for producing coated metal objects.



, J. P. MoN'NoT. METHOD OF AND APPARATUS FOR PRODUGING GOAT ED METAL OBJECTS.

APPLIUATION FILED JULY 2, 1909K Patented Oct. 11, 1910.

2 SHEETS-SHEET 1 N@ MW M( ATTO/MIE YS J. F. MONNOT.

METHOD 0F AND APPARATUS FOR PRODUUING COATED METAL OBJECTS.

uPLIoAlIoN FILED JULYz, 1909.

972,629, Patented Oct. 11, 1910.

2 SHEETS-SHEET 2.

WITNESSES HWENTO/i ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN F. MONNOT, OF NEW YORK, N. Y., ASSIGNOR TO DUPLEX BTETALS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD OF AND APPARATUS FOR FRODUCING COATED METAL OBJECTS.

Specification of Letters Patent.

Patented Oct. 11, 1910.

Application filed. July 2, 1969. Serial N0. 505,699.

To alt whom it may concern.'

lie it known that I, .Tonia F. MoNNo'r, a citizen of the United States, residing at New York, in the county of New York and State of New York, live invented certain new and useful Methods of and Apparatus for Producing Coated Metal Objects, of which the following is a specification.

My invention relates to methods of and apparatus for producing coated metal objects, particularly compound ingots comprising unlike metals weld-united, and consists in means whereby a. billet or object to be coated may be heated to a high temperature while immersed in a bath of flux or like fused protective material, and may be transferred to a mold while still submerged in such protective material, and then may have a layer of molten metal cast about it and united to it as the metal so cast solidities.

My invention further consists in the process comprising the heating of an object to be coated, Linder protection of an enveloping bath of fused protective material, transferring the object while still so envelope-d to a suitable mold, and casting a body of molten metal or other suitable material into said mold and against the surface of the heated object and causing the metal so cast to solidify against such object; the metal so cast being cast through a deep body of the molten protective material within the mold and displacing such material, the latter therefore serving as a wiping material for the molten metal, whereby the molten metal as cast is purified and freed from ent-rained and occluded gases, oXid impurities, etc.

I will now proceed to describe my invention with reference to the accompanying drawings, illustrating two forms of apparatus embodying the apparatus portion of my invention and adapted for carrying out the process, and will then point out the novel features in claims.

In said drawings: Figure 1 shows more or less diagrammatically a vertical longitudinal section of one form of the said apparatus; Fig. 2 shows a transverse section thereof on the line :c m of Fig. 1; and Fig. 3 shows 'a transverse section of the mold portion of the apparatus, on the line y-y of Fig. l, illustrating means for centering the billet in the mold. Fig. 4 shows a longitudinal vertical section of an alternative form of apparatus, adapted for use in transferring' a heated billet from a furnace to a mold, and also shows diagrammatically, a transverse vertical section of a suitable heating furnace with which such transferring apparatus is adapted to be used.

Referring first to Figs. 1, 2 and 3: in the production of compound metal ingots, comprising' unlike metals united, and particularly in the production of ingot-s consisting of a ferrous metal, such as iron or steel, surrounded by and welded to a layer of non-ferrous metal, such for example as copper, it is very important to maintain on the billet to be coated a clean metallic surface. It is also necessary or advisable, in most cases, that this billet shall be heated to a moderately high temperature, at least, before the molten metal contacts with it; and it is further desirable that this molten metal shall be cast under such conditions that all entrained or occluded gases in the metal shall be removed, also .oXid impurities, etc. In former patents I have described processes wherein a bat-h of the desired coating metal is maintained in the desired molten condition, the metal object to be coated being immersed in this bath and a portion of the molten metal surrounding said object is segregated and caused to solidify on said object. It is quite ditlicult, however, to maintain a large bath of molten metal in the desire-d condition of eXtreme purity, particularly when such metal must be maintained at the very high temperature which in most cases is required in order that a perfect weld union may result; for at such high temperature the metal is particularly subject to contamination from furnace gases, etc., and it is almost impossible to prevent such contamination altogether. Furthermore, molten metals at such high temperature seem to have a direct solvent action on other metals inserted into them, and so are liable to cumulative contamination by contact with the objects to be coated. The apparatus herein described provides means whereby the billet or other object to be coated may be protected thoroughly against contamination, and means whereby only that quantity of molten metal actually required to form the coating is brought into actual proximity to the object to be cast, and whereby such molten metal may be chilled almost immediately after casting, to a temperature suiciently low to practically obviate solution of the one metal by the other.

The apparatus illustrated in Figs. 1, 2 and 3, comprises a combined heating furnace and handling vessel, 1, comprising a cylinder having a suitable lining 2 of material adapted to withstand the action of the protective material employed (for example,l homogenized graphite, such as described in my application Sr. No. 430,097, noW Patent No. 928,470, granted July 20, 1909), such cylinder being carried by a frame 3, said frame pivoted at 4 to a pedestal 5, and being adapted to be tilted so as to swing the cylinder 1 from a horizontal to a vertical position. Suitable means is provided for so swinging frame 3, for example, a hand-wheel 6 connected through wormgearing 7 to said frame. The frame 3 comprises bands 8 embracing said cylinder 1, which hold the cylinder to the frame when the parts are tilted as shown in dotted lines in Fig. 1; and the frame is also provided with suitable bearing rollers 9, whereby rotation of the cylinder with respect to said frame is permitted; and suitable means are provided for rotating cylinder 1, for example a hand-wheel 10 adapted to rotate a gear wheel 11 intermeshing with a gear ring 12 on cylinder 1.

Cylinder l is provided in one end with an opening 13 and with a funnel-mouth 14 leading thereto. In its other end, and at a point about opposite opening 13, it is provided with another opening 15; and a suitable mold 16 is arranged to be secured against this opening 15. This mold may have a removable bottom 17. A burner 18 may project a heating flame through the interior of cylinder 1, from opening 13 to opening 15, and thence through mold 16 (the bottom 17 of the mold having been removed to permit free passage of the furnace gases through the mold and thence out.) In this way the interior of the cylinder 1- is heated, and the mold also is heated by the waste heat of the gases issuing from cylinder 1.

In carrying out my process with the ap paratus as thus far described, the cylinder 1 is charged with a suitable quantity of some suitable protective material, for example, borax or a mixture of borax and sodium silicate, and a heating flame is directed through cylinder 1 and mold 16, until such protective material is melted; or the protective material may be introduced in a molten condition, by turning the cylinder 1 upright, or nearly so, and then introducing such material and turnin the cylinder 1 back to a horizontal position, or nearly so. A billet or other object to be coated is then introduced through opening 13, and is permitted to lie within the cylinder, submerged in the molten protective material, and so protected thereby against oxidation, until said billet is sufficiently heated, the protective material at the same time dissolving from the surface of the billet so heated any traces of oxid or like impurities, if, as will ordinarily be the case, the protective flux used be one having some oxid-dissolving power. The billet having been heated sufliciently, the bottom of the mold is applied, and the cylinder 1 is rotated about its axis to bring the billet, which rolls along the bottom of the cylinder as the latter rotates, into line with mold 1G; and at the same time the cylinder 1 is tilted slightly, so that when the billet is .in line with the mold, the molten protective material cannot flow out through opening 13. The billet is then pushed into the mold, and the cylinder 1 and mold are tilted still farther, until they ar-e upright, the billet lying within the mold and being surrounded therein by molten protective material, so that here, as in the cylinder 1, its surface is protected from contamination. The bottom 17 of the mold is preferably conical, as indicated at 19, so as to center the billet in the lower part of the mold automatically, and suitable means may be employed for centering the billet in the upper part of the mold. One such means is indicated in Figs. 1 and 3, comprising a plurality of pins 20, adapted to be thrust radially into the mold, in unison, by the action of a cam ring 21; the action being similar to that of an automatically-centering chuck.

The billet having been centered in the mold, the molten coating metal may be poured into cylinder 1 through opening 13, whence it passes through the molten protective material in said cylinder, which thus becomes wiping material, into the mold, displacing as it does so the wiping material in the mold; and the molten metal is then permitted to solidify, and as soon as sufliciently solid, the mold and cylinder 1 are tilted back to horizontal position, the mold is disconnected from the cylinder, a similar mold isl applied, and the operation is repeated.

It is to be observed that the entire operation thus described takes place without exposure of the surface of the object to be coated, to contact with air or other contaminating gases; and that the molten metal, as cast, is purified by passing through the molten wiping material, and so is freed from entrained and occluded gases, oxid impurities, etc., a dense, uniform, closegrained coating metal being thereby assured. Likewise, it is not necessary to maintain large quantities of molten coating metal at a high temperature for a long time as is the case where the bath of molten metal must be large enough to permit subincl-genou of the billet to be coated and of the molding casing' thtufcin.

rlhe molten coating n'ietal is preferably cast at the very high casting tennnfrature referred to by me in prior patents as the supermolten temperature, and when so aast it unites with the lsurface of the billet, upon contact therewitl'i, producing a welded union. Since the supermoltcn coating metal tends to dissolve the metal of the billet, the mold is preferably provided with a jacket 22, and through this jacket cooling water or other suitable coolingl medium is circulated as soon as contact and union between the molten metal and the billet have taken place. T hereby the molten metal is chilled quickly to a teml'ierature such that its tendency to dissolve the metal of the billet practically disappears.

For operations requiring the use of supermolten metal, the process above described has, as stated, the. great advantage that it is not necessary to maintain a considerable quantity of molten metal at the supermolten temperature for a long time. Instead it may be maintained at ordinary casting temperature, in which condition it is not particularly subject to contamination by the air, furnace gases, etc., until it is about to be needed, and may then be heated quickly to the desired higher temperature, and immediately poured into cylinder l and mold 1G.

The cylinder l practically constitutes, it will be seen, in the first instance, an open hearth furnace, the hearth of which contains a sufficient depth of molten protective material to completely submerge the article to be heated. Later, the cylinder l constitutes handlingapparatus whereby the billet is transferred to the mold without being eX- posed above the surface of the protective material; and finally the cylinder l serves as a. container for the wiping material, and a. reservoir to receive the excess of such material displaced from the mold by the molten metal.

The mold may be provided with a suitable lining` 23 of crucible mixture, homogenized graphite, etc.

In the alternative form of apparatus, shown in Fig. 4, I provide a cylinder 24 adapted to serve as means for conveying billets from a suitable heating furnace, 25, to a mold. This cylinder 24 is mounted upon a. suitable pedestal, 26, capable of being moved about as required, and gearing 27 is provided for tilting the cylinder with respect to its pedestal. The cylinder is provided, in one end, with an opening 2S adapted to register with a similar opening 29 in the side of the heating furnace; valves 30 and 3l being provided to prevent escape of molten material from either the furnace or y cylinder 24 when openings 28 and 29 are not in registry. Cylinder il is further provided with an opening 32 throl'lgh which a. heating flame may be In'ojected into its interior, and with a valved opening 33 through which the flame gases may escape.

I have indicated the furnace 25 as being an ordinary open hearth furnace, havingl a hearth of suitable depth to contain a pool of molten protective material of sufficient depth to completely submerge the billets to be heated.

In the use of this amniratus, the billets to be heated are introduced in any customary manner into furnace 25, and are there heated. When one of the billets is suiiiciently heated, it is moved opposite opening 2t), the cyliiider 24 moved up to the. furnace so that its opening 28 registers with opening 29 and so that there is a tight joint between the cylinder and the furnace wall, valves 30 and 31 are raised, the billet (34, Fig. 4t) is pushed through openings 28 and 29 into cylinder 24, by means of a suitable bar (35, Fig. el) introduced through a small hole in the side of the furnace, which hole is normally luted with clay or the like, and then the valves 30 and 31 are lowered, the cylinder l is moved back from the furnace, a mold of the same construction as mold 16 of Fig. l is applied to opening` 28, and then the cylinder and attached mold are slightly tilted, causing the billet to slide into the mold, after which the cylinder and mold are tilted until they are upright, after which molten metal is introduced through opening 32 and caused to flow into the mold and to displace therein the molten protective or wiping material in the mold, the operation being the same as that of the structure of Fig. l. In eifect, with the structure of Fig. 4 the operation is the same as with the structure of Fig. l, save that preliminary heating of the billets is done in an open hearth furnace and the billets entering the cylinder are hot.

The advantages of this apparatus and method of procedure are, it will be seen, practically the same as those of the apparatus before illustrated, but this apparatus of Fig. 4 lends itself rather better to largescale work, as it permits a preliminary heating of the billets in large numbers at one time and in a furnace of extremely economical type.

The protective material used may be ordinary furnace slag.

Without restricting myself to any particular metals, to be coated or to be used as coating metals, in the described process, I will state that my said process is particularly intended for coating ferrous objects, such as iron, with non-ferrous high-melting metals, such as copper, and silver, and for producing ingots in which the core or base metal (ferrous metal) and the coating metal (non-ferrous metal) are Weld united. Such Weld united unlike metals I commonly term, clad metals.

In some cases it is desirable to provide the object to be coated With a thin Welded on coating of an unlike metal, before such object is passed into the mold and is there contacted With the main body of molten coating metal. Such metal of the thin coating, which then becomes an intermediate metal in the final product, may either be the same metal as the metal of the main coating, or may be a diiferent metal; for example, When the metal of the main coating is to be brass or bronze, the metal of the intermediate coating may be copper. Such intermediate coating may be applied readily in the apparatus above described, and in carrying out the process as above described, for example, in carrying out the process in the apparatus of Figs. 1 and 2, there may be, beneath the layer of flux or protective material in the barrel 1, a thin layer of metal to form the intermediate coating; and as the object to be coated is rolled around in this barrel 1, the coating metal in said barrel, if heated to the supermolten temperature, Will unite With the surface of the object to be coated, forming a thin coating thereon. If necessary, the remaining molten metal in the barrel l may be tapped off, through a suitable tap opening, before .passing the object to be coated into the mold. Or, the intermediate coating may be applied to the object, While in the barrel 1, by passing an elect-ric current from the pool of molten metal in said barrel, through the flux to the object to be coated, using the latter as a cathode.

In carrying out the process With the apparatus shown in Fig.' 4, there may be a similar pool of molten metal to form the intermediate coating, on the hearth of the furnace, and as the billet 34 is rolled over said hearth the coating Will be formed thereon, either because the coating metal is supermolten, or if necessary, by passing an electric current from the molten metal through the flux t-o the billet, using the latter as a catho-de.

In my application Sr. No. 469,016, filed December 23, 1908 I have claimed a pro-cess of coating metals comprising making the object to be coated a cathode in a bath of fused electrolyte containing a dissolved duc tile high melting different metal, such bath maintained at a temperature above the melting point of the coating metal.

What I claim is 1. A method o-f producing coated metal objects, which comprises heating a metal ar ticle to be coated While it is submerged in a bath of fused. protective material, transferring such heated object Without exposure of it above the surface of such protective material, into a suitable* mold, and casting molten metal into such mold and into contact with the surface of the said object, and permitting such molten metal to solidify against such surface.

2. A method of produciiig coated metal objects, which comprises heating a metal article to be coated While it is submerged in a bath of fused protective material, transferring such heated object Without exposure of it above the surface of such protective material, into a suitable mold, and permitting fused protective material to surround such object in said mold, and casting molten metal into the mold through such fused protective material and causing the molten metal to displace such protective material from contact with the surface of said object, and permitting the molten metal to solidify against such surface.

3. A method of producing coated metal objects, Which comprises heating a metal article to be coated While it is submerged in a bath of fused protective material, transferring such heated object without exposure of it above the surface of such protective material, into a suitable mold, and casting molten metal into such mold and into contact with the surface of the said object and quickly cooling the molten metal upon contact With said object, and permitting such molten metal to solidify against the surface of said object.

t. A method of producing coated metal objects, which comprises heating a metal article to be coated While it is submerged in a bath of fused protective material, transferring such heated object Without exposure of it above the surface of such protective material, into a suitable mold, and permitting fus-ed protective material to surround such object in said mold, and casting molten metal into the mold through such fused protective material and causing the molten metal to displace such protective material from contact With the surface of said object, and quickly cooling the molten metal upon contact With said object, and permitting themolten metal to solidify against the surface of said object.

5. Amethod of producing coated metal objects, Which comprises heating an object to be coated Within a furnace containing` a pool of fused protective material in Which pool such object is submerged, connecting to such furnace a mold and passing the object so heated, together with a portion of the fused protective material, into such mold, Without materially exposing said object above the surface of the protective material, and then casting molten coating metal into the mold and causing it to displace molten protective material therein, and permitting the molten metal to solidify against the surface of said object.

6. Apparatus for use in producing coated metal objects, comprising a vessel adapted to contain an object to be coated and containing a bath of fused protective material, and having an opening' adapted for registry of a mold therewith, and means for tilting the said vessel.

7. Apparatus for use in producing coated metal objects, comprising a vessel adapted to contain an object to be coated and containing a bath of fused protective material, and having an opening adapted for registry of a mold therewith, means for tilting said vessel and means for rotating said vessel.

8. Apparatus for forming coated metal objects comprising a vessel adapted to contain an object to be coated and containing a pool of fused protective inatei'ial enveloping such object, said vessel having in one end an opening adapted for registry of a mold therewith, and having in its opposite end another opening adapted for the projection of flame gases through said vessel.

t). Apparatus for forming coated metal objects comprising a vessel adapted to contain an object to be coated and a pool of fused protective material enveloping such object, said vessel having in one end an openingl adapted for registry of a mold therewith, and having in its opposite end another openin'g adapted for the projection of flame gases through said vessel, and means for tilting said vessel.

1t). Apparatus for forming coated inet-al objects eon'iprising a vessel adapted to contain an object to be coated and a pool of fused protective material enveloping such object, said vessel having in one end an opening adapted for registry of a mold therewith, and having iii its opposite end another opening adapted for the projection of flame gases through said vessel, means for tilting said vessel and means for rotating it.

1l. i\ppa.ratus for use iii forming coated metal objects comprising a rotatable barrel adapted to contain an object to be coated and also to contain a pool of fused protective material enveloping said object, and having in one end an opening adapted for registry of a mold therewith, and a swingingr support for said barrel adapted to permit motion thereof from an approximately horizontal to an approximately upright position.

12. Apparatus for use in forming coated metal objects comprising a rotatable bai'rel adapted to contain an object to be coated and also to contain a pool of fused'protective material enveloping said object, and having iii one end an opening adapted for registry of a mold therewith, and a swinging support for said barrel adapted to permit motion thereof from an approximately horizontal to an approximately upright position, and means for rotating said barrel With respect to said support.

13. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material enveloping such object, said vessel having in one end an opening, a mold secured in coperative juxtaposition to said opening, and means for tilting said vessel.

111. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material enveloping such object, said vessel having in one end an opening, a mold secured in cooperative juxtaposition to said opening, means for tilting said vessel, and means for rotating said vessel.

15. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material enveloping such object, said vessel having in one end an opening, a mold secured in coperat-ive juxtaposition to said opening and provided With a removable bottom plate, and means for tilting said vessel.

16. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material enveloping such object, said vessel having in one end an opening, a mold secured iii coperative juxtaposition to said opening-and provided With a removable bottom plate, means for tilting said vessel, and means for rotating said vessel.

17. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material enveloping such object, said vessel having in one end an opening, a mold secured in coperative juxtaposition to said opening and provided With means for rapid cooling of molten metal within it, and means for tilting said vessel.

18. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material enveloping such object, said vessel having in one end an opening, a mold secured in coperative juxtaposition to said opening and provided With means for rapid cooling of the molten metal Wit-hin it, means for tilting said vessel and means for rotating said vessel.

19. Apparatus for use in forming coated metal objects comprising a vessel adapted to contain an object to be coated, and also a pool of fused protective material envelopin such object, said vessel having in one engi an opening, a mold secured in coperative juxtaposition to said opening and rovided With means for centering a billet Within it, and means for tilting said vessel.

20. Apparatus for use in forming coated Within it, means for tilting said vessel and metal objects comprising a vessel adapted to means for rotating said vessel. 10 contain an object to be coated, and also a In testimony whereof, I affix my signature pool of fused protective material envelopin the presence of two Witnesses.

ing such object, said vessel having in one l JOHN F. MONNOT. end an opening, a mold secured in lcoopera- Witnesses: tive juxtaposition to said opening and pro- H. M. MARBLE,

vided with means for centering a billet FRANK E. RAFFMAN. 

